The present invention relates to a multi-layer ceramic capacitor and a method of producing the multi-layer ceramic capacitor.
Along with miniaturization of electronic devices and achievement of high performance thereof, there have recently been increasingly strong demands for miniaturization and increase in capacity with respect to multi-layer ceramic capacitors used in the electronic devices. In order to meet those demands, it is effective to enlarge internal electrodes of the multi-layer ceramic capacitor. In order to enlarge the internal electrodes, it is necessary to thin side margins for ensuring insulation properties of the periphery of the internal electrodes.
Meanwhile, in a general method of producing a multi-layer ceramic capacitor, it is difficult to form side margins having a uniform thickness because of precision in each step (e.g., patterning of internal electrodes, cutting of a multi-layer sheet, etc.). Therefore, in such a method of producing a multi-layer ceramic capacitor, as the side margins are made thinner, it is more difficult to ensure insulation properties of the periphery of the internal electrodes.
Japanese Patent Application Laid-open Nos. 2012-209539 and 2012-191164 (hereinafter, referred to as Patent Documents 1 and 2) each disclose a technique of providing side margins in a subsequent step. In other words, in those techniques, a multi-layer sheet is cut to produce a multi-layer chip including internal electrodes exposed to side surfaces of the multi-layer chip, and side margins are then provided to the side surfaces of the multi-layer chip to produce a body.
With this configuration, the body including the side margins each having a uniform thickness is obtained in the techniques disclosed in Patent Documents 1 and 2. Therefore, in the multi-layer ceramic capacitors according to those techniques, insulation properties of the periphery of the internal electrodes can be ensured also when the side margins are made thin so as to enlarge the internal electrodes.
Further, aside from the techniques disclosed in Patent Documents 1 and 2, a technique to improve connection strength of an external electrode to a body is expected for the multi-layer ceramic capacitor. Such a technique can prevent the external electrode from being peeled off from the body, and the multi-layer ceramic capacitor can thus obtain high reliability.
Japanese Patent Application Laid-open No. 2013-84871 (hereinafter, referred to as Patent Document 3) discloses a technique capable of improving connection strength of an external electrode to a body. In this technique, dummy electrodes, which are not connected to internal electrodes, are exposed in regions of a body where external electrodes are provided. In this technique, the external electrodes have good connectivity with the dummy electrodes made of metal, so that connection strength of the external electrode to the body is improved.